title: Irradiation is an early determinant of endothelial injury during hematopoietic stem cell transplantation.
abstract: OBJECTIVE
  We investigated the degree and the time course of endothelial injury in mice pretreated with lethal or reduced-intensity irradiation administered before transplantation.
  
  
  METHODS
  Six- to eight-week-old female mice were randomly allocated into three groups: lethal-intensity irradiation (8.5 Gy, group 1), reduced-intensity irradiation (5.0 Gy, group 2), or nonirradiated controls (group 3). After conditioning, circulating endothelial cells (CD31+, CD133(-), and CD45low) and peripheral blood CD4+ or CD8+ T-lymphocyte subpopulations were enumerated using flow cytometry at various times. The morphologic changes in endothelium were examined at phase-contrast light microscopy.
  
  
  RESULTS
  Circulating endothelial cells showed an earlier and higher peak in the lethal irradiation group compared with the reduced-intensity irradiation group, which exhibited a protean elevation in cell numbers. There were no visible histopathologic changes during the early stage of endothelial damage.
  
  
  CONCLUSIONS
  Lethal and reduced doses of irradiation induced endothelial injury in a dose-dependent manner. Endothelial damage may occur before graft-vs-host disease and its related complications.
authors.affiliation: Department of Immunology, Xuzhou Medical College, Xuzhou, China.
authors.forename: L
authors.initials: L
authors.lastname: Zeng
authors.forename: Z
authors.initials: Z
authors.lastname: Yan
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Du
authors.forename: X
authors.initials: X
authors.lastname: Pan
authors.forename: K
authors.initials: K
authors.lastname: Xu
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000276:immunology / Q000528:radiation effects; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000528:radiation effects; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D042783:Endothelial Cells / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D007422:Intestines / Q000276:immunology / Q000528:radiation effects; D008099:Liver / Q000276:immunology / Q000473:pathology / Q000528:radiation effects; D051379:Mice; D008807:Mice, Inbred BALB C; D010974:Platelet Aggregation / Q000528:radiation effects; D011832:Radiation Injuries / Q000473:pathology*; D012867:Skin / Q000276:immunology / Q000528:radiation effects; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects